Referring to FIG. 1, a prior art blister package 10 includes a cavity 12 that receives a contact lens solution or “packing” solution and a contact lens within the solution. The cavity 12 is covered with a sealing flat covering layer (not shown) that is detachably sealed to a flange 14 that surrounds the cavity 12. The flange 14 of the blister package 10 defines gripping areas 16 that allow a user to grip the package and unseal the covering layer to access the contact lens stored within the cavity 12. The packing solution may have any of a variety of components, additives or other substances added thereto, such as physiologically compatible surfactants, cleaning agents, wetting agents, etc., as shown, for example, in U.S. Pat. No. 5,882,687. When manufacturing some such blister packages, the contact lens is placed within the cavity 12 together with the packing solution and any components, additives or other substances added thereto, and then the covering layer is sealed to the flange 14 to seal the contact lens, solution and any additives, etc. therein. The sealed package is then terminally sterilized, such as by the application of heat or gamma radiation thereto.
One of the drawbacks associated with such prior art blister packages and apparatus and methods for filling such packages is that the additives or other substances are introduced into the package prior to terminal sterilization. As a result, additives or other substances that can be damaged by terminal sterilization cannot be used. In other situations, terminal sterilization can negatively affect the additives or other substances and/or the solution or contact lens packaged with such additives or other substances.
Another drawback associated with prior art contact lens storage containers, and apparatus and methods for introducing additives, such as medicaments, to the containers, and/or to an eye after application of a contact lens to the eye, is that a substantial portion of the medicament or other additive is located on the external or convex surface of the contact lens. When the user blinks, the fluid within the eye, such as the tear film, can relatively rapidly flush away any such medicament or other additive located on the external or convex surface of the contact lens. The flushed medicament or other additive can flow into the lacryomo nasal duct (also referred to as the lachrymal nasal duct, i.e., a duct running between the base of the eye and the nasal passageway) which can, in turn, lead to systemic absorption of the flushed additive or other substance and, in some cases, give rise to systemic side effects.
Accordingly, it is an object of the present invention to overcome one or more of the above-described drawbacks and disadvantages of the prior art.